/* ========================================================================
 * PlantUML : a free UML diagram generator
 * ========================================================================
 *
 * (C) Copyright 2009-2024, Arnaud Roques
 *
 * Project Info:  https://plantuml.com
 *
 * If you like this project or if you find it useful, you can support us at:
 *
 * https://plantuml.com/patreon (only 1$ per month!)
 * https://plantuml.com/paypal
 *
 * This file is part of PlantUML.
 *
 * PlantUML is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * PlantUML distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
 * License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 *
 * Original Author:  Arnaud Roques
 *
 *
 */
package io.kroki.server.decode.transcoder;

public class FoxSignature {

  private static final long[] masks = new long[127];
  private static final long MASK_SPACES;
  private static final long MASK_SPECIAL1;

  static {
    final String full = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0!\"#$%&'()*+,-./:;<=>?@[\\]^_{|}~";
    long m = 1L;
    MASK_SPACES = m;
    m = m << 1;
    MASK_SPECIAL1 = m;
    m = m << 1;
    for (int i = 0; i < full.length(); i++) {
      char ch = full.charAt(i);
      masks[ch] = m;
      if (ch >= 'A' && ch <= 'Z') {
        ch = (char) (ch + ('a' - 'A'));
        masks[ch] = m;
      } else if (ch == '.' || ch == '=' || ch == '-' || ch == '~')
        masks[ch] |= MASK_SPECIAL1;
      m = m << 1;
    }
    masks[' '] = MASK_SPACES;
    masks['\t'] = MASK_SPACES;
    masks['\r'] = MASK_SPACES;
    masks['\n'] = MASK_SPACES;
    masks['\f'] = MASK_SPACES;

  }

  private static long getMask(char ch) {
    if (ch < masks.length)
      return masks[ch];
    else if (ch == '\u00A0')
      return MASK_SPACES;

    return 0L;
  }

  public static long getFoxSignatureFromRealString(String s) {
    long result = 0;
    for (int i = 0; i < s.length(); i++)
      result = result | getMask(s.charAt(i));
    return result;
  }
}
